Semiconductor Die Mass Transfer Using Rollers for Precise Alignment
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Solution Overview
Problem
Conventional methods for transferring semiconductor die, particularly LED chips, are slow and expensive, especially for high-definition displays requiring millions of chips, and face challenges with alignment and spacing as resolutions improve.
Innovation Solution
A method using roller feed loops with transfer elements, including rollers, flexible rollers, and expandable rollers, that move in opposite directions with die and substrate carriers, allowing for continuous mass transfer with alignment features and adjustable pitch and placement, facilitated by flux and die release materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional transfer techniques are used for LED chips, then alignment and placement can be achieved, but transfer speed is slow and cost is high
Solution Approach 1:
The system segments the transfer process into distinct functional zones: a pickup zone where die are collected from the die carrier, a transfer zone where die are moved to the substrate carrier, and a release zone where die are deposited. This segmentation enables continuous high-speed transfer while maintaining precision through specialized mechanisms in each zone.
Solution Approach 2:
The substrate carrier acts as an intermediary element that receives die from the die carrier and transports them to the substrate. This intermediate carrier enables mass transfer by accumulating multiple die simultaneously and delivering them in groups, dramatically increasing transfer speed while reducing individual die handling costs.
2Manufacturing precision
If high-definition displays require millions of LED chips, then resolution improves, but transfer time and costs increase
Solution Approach 1:
The system maintains continuous motion of both carriers throughout the transfer process, eliminating idle periods. The die carrier and substrate carrier move continuously in opposite directions, with die being transferred at multiple points along the path, ensuring uninterrupted high-speed operation suitable for mass production of high-definition displays.
Solution Approach 2:
The substrate carrier is pre-positioned and prepared to receive die before the actual transfer occurs. Alignment features on both carriers are pre-configured to ensure precise die placement, allowing millions of chips to be transferred rapidly while maintaining the high alignment precision required for high-definition displays.
3Productivity
If roller speed increases for faster transfer, then productivity improves, but die separation and placement precision may deteriorate
Solution Approach 1:
The system dynamically adjusts roller speeds independently for the die carrier and substrate carrier while maintaining continuous motion. This dynamic speed control allows optimization of transfer rate while using alignment features and controlled release mechanisms to maintain precise die placement, resolving the contradiction between speed and precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient, cost-effective transfer of semiconductor die with enhanced alignment and adjustable placement, suitable for high-definition displays and diverse LED types, reducing transfer time and costs.
Implementation Method 1
The die stick to the roller and transfer from a die carrier to the substrate on a substrate carrier
Implementation Method 2
The die stick to the roller
Data Source
AI summary
Methods and related systems for transfer of semiconductor die and more particularly for mass transfer of semiconductor die, such as light-emitting diodes, using transfer elements are disclosed. Certain aspects relate to methods of continuous mass transfer using roller feed loops. Two carrier bars move in opposite directions, one with die and one with a substrate. The die stick to a roller and transfer from a die carrier to the substrate on a substrate carrier. In certain aspects, transfer elements may include rollers, flexible rollers, or expandable rollers. Transfer elements may further include alignment features, such as alignment pockets, that provide enhanced die alignment. In certain aspects, transfer elements may include one or more planar surfaces that rotate positions relative to the die carrier and the substrate carrier.